A power supply apparatus (battery pack) is formed by electrically connecting battery units (battery blocks) each housing cells so as to implement a high-capacity power supply apparatus (see Patent Literature 1). Usually, a battery block includes cells and a container for housing the cells, and the container is made of resin such that the container is electrically insulated from the cells. However, the resin container has low heat-dissipating property. Accordingly, a container made of a composite material of resin and metal has been presented (see Patent Literature 2) in order to increase heat-dissipating property of the container such that heat generated by the cells under operation is dissipated and the temperature of the cells is prevented from increasing. Another container including a combination of metal heat sink and insulating material has been presented as well (see Patent Literature 3).
Other related techniques have also been presented (for example, see Patent Literatures 4 to 6).
For example, Patent Literature 4 discloses a battery housing method in which an annular space between a battery cell and a case is filled with a highly heat conductive insulating material without a gap, via a hole provided on the side of a case. The invention allows the battery cell to be fixed in a case. However, since only the annular space between the battery cell and the case is filled with the insulating material, it was difficult to firmly fix one case to another. In addition, it was difficult to prevent a short-circuit and others caused by a contact between battery blocks.